Question

若x的二次方减一分之一减三x等于x加一分之A加x减一分之B,求A,B的值

Answer 1

若(1 – 3x)/(x2– 1) = A/(x + 1) + B/(x – 1) => (1 – 3x) = A(x – 1) + B(x + 1) => 1 – 3x= (A + B)x + (B – A) => A + B = -3①,B – A = 1②,联立解得A = -2和B= -1 .